Hunting for a Nazi war criminal is a painstaking process that involves decades of work – not only research, but also ensuring that the information received will hold up in court.

Famed Nazi hunter Dr. Efraim Zuroff of the Jerusalem-based Simon Wiesenthal Center spoke Sunday afternoon with Arutz Sheva in an exclusive telephone interview about his hunt while boarding a plane between two cities in eastern Europe.

Zuroff is currently hot on the trail of a senior Nazi involved in the deportation of Jews to Auschwitz who is still alive, and who he is hoping to be able to expose in a few weeks.

The Nazi, Zuroff told Arutz Sheva, came to light after an informant contacted the Wiesenthal Center in response to publicity about reward money for information leading to the conviction of the criminal.

"In return for the reward that we were offering – and that is still to be offered,” said Zuroff, “the informant is willing to give information. This includes evidence in the form of documents and [live] testimony at the trial,” he explained.

The process is not as simple as it appears, however. Gathering evidence is by no means the end of the work – nor, for that matter, is it even really the beginning.

"We don't even know if the country in which the person committed the atrocities will be willing to charge [the Nazi war criminal] with the crimes [in the first place],” Zuroff added.

And if not? Does the informant then receive the reward he sought in exchange for the evidence he gave?

"No.”

Although an informant might feel frustrated after coming forward with evidence and/or perhaps having taken a risk to provide information, Zuroff is clearly focused on the task at hand: decades of searching is coming down to a very small window of time that is rapidly closing.

As for the informant's feelings on the matter: “That's his or her problem,” Zuroff said.